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Amortization period for the recovery of regulatory asset, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	us-gaap_RegulatoryAssetAmortizationPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
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The amount for the individual regulatory asset as itemized in a table of regulatory assets as of the end of the period.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 340
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382

Name:	us-gaap_RegulatoryAssets
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Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are expected to be recovered through revenue sources within one year or the normal operating cycle, if longer. Such costs are capitalized if they meet both of the following criteria: a. It is probable that future revenue in an amount at least equal to the capitalized cost will result from inclusion of that cost in allowable costs for rate-making purposes. b. Based on available evidence, the future revenue will be provided to permit recovery of the previously incurred cost rather than to provide for expected levels of similar future costs. If the revenue will be provided through an automatic rate-adjustment clause, this criterion requires that the regulator's intent clearly be to permit recovery of the previously incurred cost.

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Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are not expected to be recovered through revenue sources within one year or the normal operating cycle if longer.

Name:	us-gaap_RegulatoryAssetsNoncurrent
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Number of utilities filing a joint proposal

No definition available.

Name:	wec_NumberOfUtilitiesFilingAJointProposal
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Data Type:	xbrli:integerItemType
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Name:	us-gaap_RegulatoryAssetAxis=wec_EnergyCostsRecoverableThroughRateAdjustmentsMember
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Name:	us-gaap_RegulatoryAssetAxis=us-gaap_AssetRecoverableGasCostsMember
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Name:	us-gaap_RegulatoryAgencyAxis=wec_IllinoisCommerceCommissionICCMember
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Name:	dei_LegalEntityAxis=wec_WisconsinElectricPowerCompanyMember
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Name:	us-gaap_RegulatoryAgencyAxis=wec_PublicServiceCommissionOfWisconsinPSCWMember
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Data Type:	na
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Name:	dei_LegalEntityAxis=wec_WisconsinGasLLCMember
Namespace Prefix:
Data Type:	na
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Name:	dei_LegalEntityAxis=wec_WisconsinPublicServiceCorporationMember
Namespace Prefix:
Data Type:	na
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Name:	dei_LegalEntityAxis=wec_ThePeoplesGasLightAndCokeCompanyMember
Namespace Prefix:
Data Type:	na
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Name:	dei_LegalEntityAxis=wec_NSGMember
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Name:	dei_LegalEntityAxis=wec_MinnesotaEnergyResourcesCorporationMember
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